I replaced the front strut cartridges myself about a year ago in my 88 760 and found the job easier than had been with my previous 240 for the reason that in the case of the 760, I didn't have to disconnect the brake lines from the strut assembly. As I recall, I went through the following steps:

1. Inside the engine compartment, you'll notice that the top of the strut assembly has 2 bolts which secure the strut/spring assembly to the chassis. These 2 bolts are all you need removed to allow the assembly to pull out from the top and then swing outwards with its base still secured.
2. BEFORE you remove these 2 bolts you'll need:

a- a spring compressor which you should be able to borrow at an automotive parts store, and if that's not available to you, to rent from almost any rental shop.

b- an air impact wrench to loosen the large nut at the top of the strut or the piston rod. This nut is not impossible to remove with conventional wrenches if you have a box-end that'll reach deep enough to allow you to hold the top of the rod from turning. The impact wrench will handle the job without having to prevent the shaft (or rod) from turning. An alternative if you don't have an air tools, is to stop by a tire shop or any place that has air wrenches and get them to simply loosen that centre nut for you. Then you can take the car back home and, at the proper step, remove the nut with a wrench. You can do the same for the re-install and have them torque it down for you.
3. Remove the front wheel.
4. Remove the bolts from the braket that secure the brake hoses to the wheel well.
5. Disconnect the stabilizer bar (this is to allow the wheel assembly to drop sufficiently. I can't remember if I also disconnected the tie-rod end.
6. Secure a piece of haywire or its equivalent to the top of the strut assembly and to the car chassis inside the wheel well so that when you remove the 2 nuts from the engine compartment, the assembly is not allowed to swing out more than about a foot. Any more of a swing-out than that will result in damage to the brake lines. Also, using a piece of masking tape, mark out the location of the 2 top nuts. This sets part of your wheel alignment (castor, I believe).
7. Remove the 2 nuts inside the engine compartment.
8. Swing out the assembly and compress the spring. Once the spring is compressed sufficiently to remove the pressure against the top plate, remove the large centre nut. You can now pull out the spring.
9. With the spring out of the way, all that's left to do is to remove the large flat nut that holds the cartridge in place. A large pipe wrench will do in a pinch or you can simply tap it unscrewed with a chisel. Be carefull on the reinstall that you do not make contact with the piston rod. Treat it as if it were made of glass.
10. Pull out the insert, put the new one in. Simple as that!
11. Reverse the process for reinstall.
One word of caution: treat the compressed spring with respect. If the spring compressor ever lets go, you have got a lot of energy to contend with.
Good luck if you decide to go through with it.